The prevalence of obesity and diabetes is increasing at an alarming rate. According to WHO, in 2008, 70% of the U.S. adult population was overweight, and among them 33% were obese. Parallel to the explosive number of people becoming overweight and obese, in 2008, it was estimated that 12.3% of the U.S. population had elevated blood glucose [http://www.who.int/diabetes/facts/en/]. The obesity/diabetes epidemic is not unique to the U.S. According to WHO (Fact Sheet No. 312, September 2012), 347 million people worldwide have diabetes. Treating obesity and improving glycemic control effectively and safely remain major challenges for modern medicine.
Monoacylglycerol acyltransferase 2 (MGAT2) has emerged as an attractive target for the treatment of obesity and type II diabetes [Yen, C. L. et al., Nat. Med., 15(4):442-446 (2009)]. MGAT2 is highly and selectively expressed in the small intestine where it exerts a pivotal role in the monoacylglycerol-pathway for the absorption of dietary fat.
When dietary fat is ingested, pancreatic lipase digests triglycerides into free fatty acids and 2-monoacylglycerol, which are absorbed by intestinal epithelial enterocytes. Once inside enterocytes, free fatty acids and 2-monoacylglycerol are used as building blocks to resynthesize triglycerides by two sequential acylation steps; first by MGAT and then by DGAT enzyme reactions. Triglycerides are then incorporated into chylomicrons and secreted into lymph to be utilized as an energy supply for the body. MGAT2 knockout mice exhibit a healthy metabolic phenotype and show resistance to high-fat diet induced obesity, improvement in insulin sensitivity and decreased fat accumulation in liver and adipose tissue. In addition, genetic deletion of MGAT2 produces mice with increased levels of GLP1 [Yen, C. L. et al., Nat. Med., 15(4):442-446 (2009)]. Taken together, these data show that MGAT2 inhibitors hold promise to treat metabolic disorders such as obesity, type II diabetes and dyslipidemia.